-LRB- CNN -RRB- -- Mark and Kristine Wathke knew they were going to die .

Stuck in a foot of snow on a road somewhere outside Yellowstone National Park in Wyoming , the couple from Wisconsin pulled all the clothes out of their suitcases and wore them , trying to keep warm in their car with temperatures dipping below zero .

They rationed the bread and water they had with them , and ran the car 's engine periodically to get some heat . There was no service for their cell phone .

This was n't the end they 'd envisioned for their national parks tour .

The Wathkes left Yellowstone 's northeast entrance on October 29 at 4 p.m. , planning to head to Montana . They plugged the address for their hotel into Google Maps and hit the road . Their route took them on Beartooth Highway , but they said they did n't see any signs warning that the road was closed .

In fact , the highway was shut down in mid-September due to heavy snow , with signs posted saying so , the Park County Sheriff 's Department said .

The Wathkes ' Kia got stuck several miles in . They thought for sure they 'd be found , probably the next day . But it did n't happen , and with each passing day , their hopes dimmed , they told the Billings Gazette .

They decided to write letters to loved ones , and recorded a message saying goodbye .

Meanwhile , Troy Barnett , who owns the K Bar Z Guest Ranch near Cody , Wyoming , heard about the missing couple when his wife spotted it on Facebook Sunday night .

`` I decided about 9 o'clock that it was too late to go out , '' Barnett told CNN .

Monday morning , Barnett got out the snowmobile he had n't used since last fall , made sure it was in running order , loaded it into his pickup truck and set out to look for the Wathkes .

`` There are only two roads in this area , so I kinda knew what road they needed to be on , '' he said .

He drove for more than 20 miles , until he could n't anymore because of the snow . Then he got on the snowmobile and minutes later , found the couple just about where he thought they 'd be .

`` The car was stuck in the middle of the road . It was n't buried but it had some snow on top of it . It kind of worried me a bit , and there was no movement , '' Barnett remembered .

Inside the car , the couple heard something .

`` Mark heard it first and he was like , ` Kris ! Kris ! Kris ! , ' '' Kristine Wathke told the Billings newspaper . `` We saw him coming up the road and I was just crying . ''

Barnett parked right next to the vehicle , and the door opened .

`` They were really grateful and there were some tears , '' he said . `` I asked if everyone was okay and if they need medical attention and if they were warm enough . ''

Barnett loaded Mark and Kristine on his snowmobile and drove back to his truck . He called a friend with a radio and had him get in touch with the sheriff , and then took the couple to his house , where they called their family .

The sheriff says Barnett 's actions saved the Wathkes ' from serious harm .

`` I commend him for his unselfishness , '' Sheriff Scott Steward said .

Barnett said it 's not the first time he 's helped someone in that area .

`` We help people off there quite a bit , '' he said . `` It 's really rural up here , we 're just up in the mountains . ''

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CNN 's Sara Ganim and Amanda Watts contributed to this report

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The Wathkes were touring national parks when they got stuck in Wyoming

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They rationed bread and water to survive , turned heater on periodically

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Rancher Troy Barnett had an idea where they might be